DE102010009003A1 - Endoscopic instrument, has shaft including wall made up of electro-active polymer, and reference-and control electrodes connected with each other by elastic connecting webs, which are arranged within radially expansion of electrodes - Google Patents

Abstract

The instrument has a shaft (4) including a bendable portion (6) that is bent in longitudinal direction and including a wall made up of an electro-active polymer. A set of reference-and control electrodes is embedded in the wall and rotationally arranged in axial direction. The reference-and control electrodes are connected with each other by elastic connecting webs, which are arranged within a radially expansion of the reference-and control electrodes. The connecting webs comprise a smaller radial expansion than the reference-and control electrodes.

Description

The invention relates to an endoscopic instrument having a shaft which, viewed in the longitudinal direction, has at least one bendable section.

For example DE 10 2008 047 776 For example, an endoscopic instrument is known, which has a shaft section made of an electroactive polymer, wherein electrodes for activation are embedded in the electroactive polymer. These electrodes are designed as tooth-shaped interlocking structures.

Out DE 10 2009 036 424 Also, an instrument is known with a shaft portion made of an electroactive polymer, in which the individual electrodes are interconnected by webs located on the outer or inner circumference of the electrode structure.

In view of this known prior art, it is an object of the invention to improve an improved endoscopic instrument with a shaft having in the longitudinal direction at least one bendable portion having a wall of an electroactive polymer in that the space utilization is optimized and the mechanical efficiency is increased.

This object is achieved by an endoscopic instrument having the features specified in claim 1. Preferred embodiments will become apparent from the subclaims, the following description and the accompanying figures.

The endoscopic instrument according to the invention has a shaft which, viewed in the longitudinal direction, has at least one bendable section. This bendable portion has a wall or wall region of an electroactive polymer, in which a plurality of control and reference electrodes arranged alternately in the axial direction are embedded. By applying a voltage between the control and reference electrodes, deformation of the electroactive polymer located between the electrodes is achieved. By arranging a plurality of electrode pairs formed from control and reference electrodes in the axial direction one behind the other, the total deflection or shape change is amplified, so that a desired bending or curvature of the instrument can be achieved by applying a voltage to desired electrodes. In order to be able to control the flexibility in a targeted manner, it is possible that sections located one behind the other in the axial direction can be selectively activated differently by selectively applying electrical voltage between reference and control electrodes in individual sections. In this way, for example, a serpentine deformation of the bendable portion can be achieved.

According to the invention, the space in the wall of the bendable section is optimized in that the control electrodes and the reference electrodes are connected to each other via connecting webs which are located within, preferably completely within, the radial extent of the control and reference electrodes. This means that a plurality of control electrodes or sections of the control electrodes are interconnected via connecting webs and a plurality of reference electrodes or portions of the reference electrodes are interconnected via connecting webs. Control and reference electrodes are electrically isolated from each other by the intervening electroactive polymer. According to the invention, the connecting webs, which connect the control electrodes, and the connecting webs, which connect the reference electrodes with each other, are not laterally, d. H. arranged on the outer circumference or on the inner circumference of the electrodes, but within the radial extent. By this arrangement, a larger electrode area can be created in the radial direction, whereby the efficiency is increased, since the available space in the radial direction is optimally utilized. Thus, viewed in the radial direction, the connecting webs can be arranged in a central region of the wall, so that the reference electrodes and the control electrodes preferably protrude in the radial direction with respect to the connecting webs outwardly and inwardly.

Preferably, the reference electrodes and / or the control electrodes are rigid. In this way, the electrodes provide for a mechanical reinforcement of the wall and also define a fixed shape, whereby a defined deflection is realized upon application of a voltage.

To prevent the deformation of the electroactive polymer between the electrodes, i. H. each to allow between a control and a reference electrode, they must be able to move to a certain extent towards each other or away from each other. To favor this, the connecting webs between the control electrodes and / or the connecting webs between the reference electrodes are preferably designed to be elastic, so that they allow the described movement between reference and control electrodes upon deformation of the wall or its electroactive polymer.

More preferably, the connecting webs have a smaller radial extent, as the reference and control electrodes. It can thereby be achieved that the reference and control electrodes, as described above, protrude radially inwards and outwards relative to the connecting webs and, viewed in the radial direction, the connecting webs occupy only a smaller part of the wall. Preferably, the connecting webs are arranged centrally in the interior of the wall.

More preferably, the first connecting webs, which connect the control electrodes to each other and the second connecting webs, which connect the reference electrodes with each other, arranged offset in the radial direction to each other. This means that the first connecting webs and the second connecting webs can preferably be arranged next to each other and spaced apart in the radial direction, wherein, for example, the first connecting webs are arranged in the radial direction more inwardly than the second connecting webs in the wall or vice versa. This means that the first and second connecting webs extend in the wall at a distance from each other without touching each other. Due to the embedding in the wall, the electroactive polymer material or another suitable separating layer for electrical insulation is also preferably arranged between the connecting webs.

According to a further preferred embodiment of the invention, the control electrodes and / or the reference electrodes are plate-shaped. In this case, the individual electrodes preferably extend as flat plates, more preferably in a direction orthogonal to the longitudinal axis of the shaft, d. H. in diameter planes. As a result, an optimal space utilization is achieved with high efficiency. At the same time an optimal stabilization of the shaft is achieved in the radial direction, since in this direction the electrodes have a particularly large extent. In this way, an undesirable deformability of the shaft is prevented in the radial direction.

According to a further preferred embodiment, a plurality of individual control electrodes and reference electrodes are arranged distributed over the circumference of the shaft, wherein the connecting webs are arranged in radially extending parting lines between the individual electrodes. The individual electrodes may be formed in the form of strip-shaped sections which extend at a distance from each other in the radial direction. A plurality of such sections is arranged over the entire circumference of the wall, preferably uniformly distributed. In this way, on the one hand, the described stability in the radial direction is achieved, while at the same time ensuring the desired bendability of the shaft. The connecting webs can be arranged to save space in the joints. In this case, the connecting webs engage the individual electrodes in each case at the radially extending edges, which face the joints, at. The connecting webs preferably each extend between adjacent control electrodes, wherein a reference electrode is located in each case between these adjacent control electrodes. Correspondingly, connecting webs extend between two adjacent reference electrodes, wherein a respective control electrode is located between these reference electrodes. In this case, the connecting webs preferably extend inclined to the axial direction of extension of the wall, d. H. obliquely between facing radial edges of the electrodes to be connected. Ie. a connecting land engages a first electrode at a first radial edge and engages the adjacent second electrode at the second circumferentially oppositely facing radial edge. In this arrangement of oblique connecting webs, the connecting webs intersect between the control electrodes seen in a radial projection.

To optimize this arrangement, arranged in the individual electrodes, which are arranged distributed in the circumferential direction, so arranged that alternate even in a diameter plane in the circumferential direction control electrodes and reference electrodes. At the same time, control and reference electrodes also alternate in the axial direction. In this way, it becomes possible to connect in the parting lines the control electrodes adjacent each other in two axial columns via zigzag-shaped connecting webs and correspondingly connect the reference electrodes arranged in two adjacent axial gaps to one another in a zigzag manner via connecting webs.

More preferably, at least individual control and / or reference electrodes in the radial direction in each case in at least two, more preferably in three or more electrode parts are divided, which are electrically conductively connected to each other. In this case, the electrode parts can be connected via electrically conductive connecting webs, which are preferably formed integrally with the electrode parts. However, the connecting webs are preferably narrower in the circumferential direction than the adjacent electrode parts. Also by this configuration, the desired bendability is achieved while maintaining strength in the radial direction. Furthermore, an optimal distribution of the electrode surface is ensured in the entire wall cross section, while at the same time the electrode surface can be minimized. This too Increases the mechanical efficiency, since the mechanical efficiency and the compression modulus of the electrode assembly in conjunction with the elastomer located between two electrodes is related to the ratio of the electrode surface to the elastomer border of the electrodes. For this reason, it is desirable to subdivide the actual electrode surface into smaller segments, wherein in turn between the electrode segments filled with the elastomer or electroactive polymer free spaces arise.

According to a further preferred embodiment, at least individual control and / or reference electrodes or their electrode sections may be formed at least in part by a meander-shaped electrode track or a comb-like arrangement of electrode tracks. In turn, free spaces, which are filled with the electroactive polymer, arise between the electrode tracks. In this way, the electrodes can preferably extend substantially over the entire cross section of the wall. Particularly preferably, the electrode sections are each subdivided into three electrode parts, which lie next to one another in the radial direction and are connected to one another via fixed webs. The electrode parts and the webs connecting them each extend preferably in a diameter plane relative to the longitudinal axis of the shaft. The middle of the three electrode parts is preferably connected to the connecting webs for connection to the adjacent similar electrodes. Accordingly, the connecting webs are preferably in the radial extent of the central electrode part. Starting from the middle electrode part, then preferably extend to both sides, d. H. radially inwardly and radially outwardly, in each case a further electrode part, which in turn can then optionally be subdivided into further smaller electrode parts. In particular, these radially inner and outer electrode parts may be formed by a meander-shaped electrode track or may have a comb-like arrangement of electrode tracks or electrode parts.

Expediently, the at least one bendable section, as seen in the circumferential direction, has at least two separately activatable actuator fields or actuator chords. In each of these, a multiplicity of control and reference electrodes arranged alternately in the axial direction are arranged, wherein at least the control electrodes of one actuator field are electrically insulated from the control electrodes of the other actuator field. In this case, a plurality of strip-shaped control and reference electrodes can in turn be arranged next to each other in the circumferential direction in each actuator field, as described above. The control electrodes of the individual actuator fields can be acted upon separately with voltage, so that the actuator fields can be activated separately and the shaft can thus be deformed independently in different circumferential regions independently of one another in order to enable a deflection in different radial directions. For this purpose, at least three actuator fields, which are expediently distributed uniformly over the circumference, are preferably provided for this purpose. In addition, several Aktorfelder, as described above in the axial direction are arranged one behind the other, in order to specifically deform axial portions of the shaft selectively different, so that, for example, a serpentine bending of the shaft is possible.

While the control electrodes of the individual actuator fields are electrically insulated from one another, the reference electrodes of at least two actuator fields are preferably electrically conductively and / or mechanically interconnected, wherein preferably the reference electrodes of the actuator fields located in a diameter plane are interconnected. For example, the circumferentially adjacent reference electrodes may be connected to each other in the circumferential direction or obliquely to this extending webs. As a result of this mechanical connection, the overall structure of the electrode arrangement becomes more stable, so that the dimensional stability of the shaft, in particular in the radial direction, is also increased. At the same time, the number of required electrical connections is minimized.

More preferably, the reference electrodes of the at least two Aktorfelder in the axial direction on a common electrical connection. Ie. the reference electrodes must not be connected to each other in the axial direction in each actuator field, but this axial connection z. B. be displaced in an actuator field, while the reference electrodes of the other Aktorfelder are connected via connections in the circumferential direction, preferably always located in a diameter plane or adjacent to these reference electrodes or reference electrode sections are interconnected. This is preferably done over itself in the circumferential direction or obliquely to this extending connecting webs. This connecting webs can be located radially offset from the connecting webs, which interconnect the control electrodes, as described above. In this case, the connecting webs extend through the radial parting lines, which separate the electrodes in the circumferential direction from each other. Instead of arranging the axial connections for axially successive reference electrodes in only one Aktorfeld, it is also possible to distribute the axial connections over several Aktorfelder, then alternate, for example, the axial connections between the individual Aktorfeldern. Ie. For example, seen in the axial direction is a first layer of reference electrodes connected to a second layer of reference electrodes in a first actuator field via one or more webs, while a second and a third layer of reference electrodes in the axial direction in a second actuator array are connected to each other, and so on.

The control electrodes and / or the reference electrodes are further preferably integrally formed with the connecting webs connecting them. In this way, the overall structure of the electrode structure is simplified, since connection operations for connecting the individual parts or sections and connecting webs can be dispensed with. This simplifies assembly. In addition, the mechanical stability is increased. Furthermore, the reliability can be increased because the risk of missing contact between individual elements is avoided due to the one-piece design of these elements.

The invention will now be described by way of example with reference to the accompanying drawings. It shows:

1 an overall view of an endoscopic instrument according to the invention,

2a a schematic view of the bendable portion of the shaft of the endoscopic instrument,

2 B schematically the bendable portion in the bent state,

3 schematically the electrode arrangement in an actuator field,

4 schematically the electrode arrangement in three adjoining actuator fields,

5a a schematic side view of the electrode assembly according to 3

5b a plan view of the electrode assembly according to 5a .

6 a top view of an electrode assembly according to a second embodiment of the invention,

7 a perspective view of the electrode assembly according to 6 .

8th a schematic view of the electrode assembly according to 7 in the bent state,

9 a perspective view of an electrode assembly according to 5a and 5b .

10 a schematic perspective view of an electrode assembly according to another embodiment of the invention,

11 a schematic perspective view of an electrode assembly according to another embodiment of the invention,

12 an electrode arrangement according to 7 and 8th in a bent state to a ring,

13 a perspective view of an electrode assembly according to another embodiment of the invention and

14 an enlarged perspective view of the electrode design according to another embodiment of the invention.

1 shows the overall view of an endoscopic instrument according to the invention. The endoscopic instrument has a handle at the proximal end 2 and a shaft extending distally therefrom 4 on. The shaft 4 has a bendable section in the region of its distal end 6 on. The bendable section 6 is made of an electroactive polymer. Ie. the wall of the bendable portion is made of the electroactive polymer in which a plurality of electrodes for activating and deforming the electroactive polymer are embedded. The electrodes are as in 2a shown in multiple actuator fields 8th summarized. In the example shown here are three axially extending Aktorsehnenhnen 10 formed, the a plurality of axially one behind the other arranged Aktorfelder 8th exhibit. Due to the arrangement of three Aktorsehnen are thus three Aktorfelder 8th over the circumference of the shaft of the bendable section 6 distributed. Depending on which peripheral side the actuator fields 8th can be activated by applying an electrical voltage to the electrodes, which are embedded in the electroactive polymer, a curvature of the actuator axis X can be achieved in a certain radial direction, as shown schematically in FIG 2 B is shown.

According to the invention, the electrodes are now in an optimized manner into the electroactive polymer of the bendable section 6 of the shaft 4 embedded.

3 shows schematically the structure of an actuator field 8th or part of an actuator field 8th , In the electroactive polymer is a plurality of reference electrodes 12 and control electrodes 14 embedded. These are control electrodes 14 and reference electrodes 12 arranged in the axial direction X alternately to each other, wherein the electrodes are spaced from each other, so that between the Electrodes is the electroactive polymer, which is deformed by applying an electrical voltage to the electrodes due to the electric field. The reference electrodes 12 and control electrodes 14 each extend only over very small peripheral portions and thus form individual electrode sections, ie reference electrode sections 12 and control electrode sections 14 , Within the actuator field are the individual reference electrodes 12 or reference electrode sections electrically connected to each other and the individual control electrodes 14 or the control electrode sections are electrically connected to each other. These are elastic webs 16 and 18 intended. The elastically formed connecting webs 16 connect the reference electrodes 12 and the elastic connecting webs 18 connect the control electrodes 14 among themselves. In this case, these connecting webs extend 16 . 18 between the electrodes 12 and 14 in radial joints 20 , which in the radial direction between the individual electrodes or electrode sections 12 . 14 run. In this case, the connecting webs extend 16 . 18 inclined or oblique to the diameter plane with respect to the longitudinal axis X.

Further, the reference electrodes 12 and control electrodes 14 in circumferentially adjacent columns 22 offset in the axial direction X, so that always a control electrode 14 seen in the circumferential direction in the same diameter plane next to a reference electrode 12 lies. Ie. Also in the circumferential direction, reference and control electrodes alternate. In this way, as always adjacent electrodes of two adjacent columns 22 interconnected, the way over which the connecting bridges 16 . 18 extend, shortened. The connecting bridges 16 and 18 are spaced apart in the radial direction, as in FIG 5b is shown. It always extends a connecting bridge 16 cruising at a connecting bridge 18 offset in the radial direction. So are the connecting bridges 16 and 18 isolated against each other. The connecting bridges 16 and 18 engage the radially extending longitudinal edges of the reference electrodes 12 and 14 in the area of the joints 20 at. They lie, as in 5b can be seen completely within the extension in the radial direction r of the arrangement of reference electrodes 12 and control electrodes 14 ,

The circumferentially adjacent Aktorfelder 8th the three actor sons 10 are designed so that at their Steuerlektroden 14 an electrical voltage can be applied separately, as indicated by 4 is explained. Within the individual actuator fields 8th , what a 4 are shown are the control and reference electrodes 14 . 12 over connecting bridges 16 and 18 as interconnected as based on 3 explained. Between the in 4 shown three actuator fields 8th are only the reference electrodes 12 through connecting bridges 16 connected with each other. Ie. in the three actor fields 6 separating joints 20 are only the connecting bridges 16 but not the connecting bridges 18 arranged. It is achieved that all reference electrodes 12 are interconnected, de control electrodes 14 but only within an actuator field 8th connected to each other, so that the three actor fields 8th can be acted upon separately from each other with an electrical voltage to the electroactive polymer targeted in individual Aktorfeldern 8th to be able to deform.

5b shows a plan view of the electrode assembly according to 5a , which essentially corresponds to the arrangement which in 3 is shown. In 5b is the spacing of the connecting webs 16 and 18 to recognize in the radial direction r. In addition, it can be seen that the connecting webs 16 and 18 not in the radial direction r over the electrodes 12 and 14 extend, ie completely within the radial extent of the electrodes 12 and 14 are located.

6 shows an alternative embodiment in a plan view accordingly 5b , In this case, the reference electrodes 12 in each case three reference electrode parts 12a . 12b and 12c on which lie next to each other in the radial direction r. Accordingly, the control electrodes 14 three control electrode parts 14a . 14b and 14c on, which lie next to each other in the radial direction. The middle electrode parts 12b and 14b are as described above on the connecting webs 16 and 18 interconnected. These thus essentially correspond to the arrangement of the reference electrodes 12a and control electrodes 14 according to the 3 to 5 , The control electrode parts 14a and 14c are in the radial direction r from the central control electrode part 14b in front. Accordingly, the reference electrode parts 12a and 12c in the radial direction from the central reference electrode part 12b in front. The connecting bridges 16 and 18 lie in the middle range, ie within the radial extent of the middle electrode parts 12b and 14b , The outer electrode parts 12a . 14a such as 12c and 14c are with the middle electrode parts 12b and 14b over connecting bridges 24 , which extend substantially in the radial direction r, connected. Here are the electrode parts 12a . 12b and 12c with their intermediate connecting webs 24 and the connecting webs 16 preferably formed in one piece. Accordingly, the control electrode parts 14a . 14b and 14c with their connecting connecting webs 24 and the connecting webs 18 preferably formed in one piece.

7 shows the arrangement according to 6 once again a perspective view. The views according to 3 to 7 have each shown the electrode assembly in its unwound, planar shape. For placement in the wall of the bendable section 6 of the shaft, this arrangement is curved so that it can extend in the circular wall. This is in terms of based on 6 and 7 described electrode assembly in 8th shown there is the arrangement according to 7 shown curved. 12 shows corresponding to the substantially fully curved ring, wherein in the embodiment shown there thirteen Aktorfelder 8th or actor struts 10 arranged distributed over the circumference.

9 shows a perspective view of the electrode assembly as shown in FIG 5a and 5b is shown in side view and plan view. 10 shows in a perspective view a variant of this electrode arrangement, wherein at the reference electrodes 12 and control electrodes 14 radially projecting projections 26 are formed. These projections 26 form spacers, which have a sufficient displacement space for the dialectic, ie between the electrodes 12 and 14 ensure located electroactive polymer.

11 shows a perspective view of a variant of the embodiment according to 9 , In this variant, the control electrodes extend 14 and reference electrodes 12 over a longer range in the radial direction r, so that they protrude in the radial direction r inwardly and outwardly beyond the central region, in which the connecting webs 16 and 18 are arranged. In this way, a larger electrode area in the radial direction, ie created in the direction of the wall thickness of the shaft.

13 shows a variant of the embodiment according to 11 wherein the radially inwardly and outwardly projecting portions of the reference electrodes 12 and control electrodes 14 which protrude radially beyond the central portion in which the connecting webs 16 and 18 attack, comb-like structures 28 exhibit. The comb-like structure 28 is formed by a plurality of parallel to each other substantially in the radial direction r extending electrode paths. In this case, the electrode tracks of the comb-like structure extend from the central central region of the control electrodes 12 and 14 radially inwards or outwards.

14 now shows a further embodiment in which the reference electrodes 12 and control electrodes 14 in each case by a meandering electrode path 30 be formed. In this case, the electrode tracks run 30 over an area substantially the extent of the reference electrodes 12 and control electrodes 14 at the in 11 shown embodiment correspond. The design of the comb-like structures 28 and the meandering electrode tracks 30 has the advantage that the electrode area is minimized relative to its peripheral edge, or the peripheral edge is maximized. In this respect, the ratio of the electrode area to the electrode border, at which the electroactive polymer is adjacent, is reduced, whereby the mechanical efficiency can be increased.

LIST OF REFERENCE NUMBERS

2

handle

4

shaft

6

bendable section

8th

actuator fields

10

Aktorsehnen

12

reference electrodes

14

control electrodes

16, 18

connecting webs

20

joints

22

columns

24

connecting webs

26

projections

28

comb-like structures

30

Meander-shaped electrode track

X

axial direction, longitudinal axis of the shaft

r

radial extent

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008047776 [0002]
• DE 102009036424 [0003]

Claims (14)

Endoscopic instrument with a shaft ( 4 ), which viewed in the longitudinal direction (X) at least one bendable portion ( 6 ), which has a wall of an electroactive polymer, in which a plurality of axially in the axial direction arranged control ( 14 ) and reference electrodes ( 12 ), the control electrodes ( 14 ) and the reference electrodes ( 12 ) each via connecting webs ( 16 . 18 ), which within the radial extent of the control ( 14 ) and reference electrodes ( 12 ) are located. Endoscopic instrument in which the reference electrodes ( 12 ) and / or the control electrodes ( 14 ) are rigid. An endoscopic instrument according to claim 1 or 2, wherein the connecting webs ( 16 . 18 ) are elastic. Endoscopic instrument according to one of the preceding claims, wherein the connecting webs ( 16 . 18 ) a smaller radial extent than the reference ( 12 ) and control electrodes ( 14 ) exhibit. Endoscopic instrument according to one of the preceding claims, in which first connecting webs ( 18 ), which the control electrodes ( 14 ), and second connecting webs ( 16 ), which the reference electrodes ( 12 ) connect to each other, in the radial direction (r) offset from one another. Endoscopic instrument according to one of the preceding claims, in which the control electrodes ( 14 ) and / or the reference electrodes ( 12 ) are plate-shaped. Endoscopic instrument according to one of the preceding claims, in which the control electrodes ( 14 ) and the reference electrodes ( 12 ) are formed from a plurality of individual circumferentially adjacent electrode sections, wherein the connecting webs in radially extending parting lines ( 20 ) are arranged between the individual electrode sections. Endoscopic instrument according to one of the preceding claims, in which at least individual control ( 14 ) and / or reference electrodes ( 12 ) or their electrode sections in the radial direction (r) in each case in at least two electrode parts ( 12a . 12b . 12c . 14a . 14b . 14c ) are subdivided, which are electrically connected to each other. Endoscopic instrument according to one of the preceding claims, in which at least individual control ( 14 ) and / or reference electrodes ( 12 ) or the electrode sections thereof at least in part by a meander-shaped electrode track ( 30 ) or a comb-like arrangement ( 28 ) are formed by electrode tracks. Endoscopic instrument according to one of the preceding claims, in which the at least one bendable section ( 6 ) seen in the circumferential direction at least two separately activatable Aktorfelder ( 8th ), in each of which a plurality of axially in the axial direction arranged control ( 14 ) and reference electrodes ( 12 ), wherein at least the control electrodes ( 14 ) of the one actuator field ( 8th ) with respect to the control electrodes ( 14 ) of the other actuator field ( 8th ) are electrically isolated. An endoscopic instrument according to claim 10, wherein the reference electrodes ( 12 ) at least two Aktorfelder ( 8th ) are electrically conductively and / or mechanically interconnected. An endoscopic instrument according to claim 10 or 11, wherein the reference electrodes ( 12 ) the at least two actuator fields ( 8th ) in the axial direction (X) have a common electrical connection. Endoscopic instrument according to one of the preceding claims, in which the control electrodes ( 14 ) and / or the reference electrodes ( 12 ) and the respective connecting connecting webs ( 16 . 18 ) are integrally formed. An endoscopic instrument according to claim 10 or 11, wherein the bendable portion (Fig. 6 ) seen in the axial direction at least two separately activatable Aktorfelder ( 8th ) having.

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